The treatment of an individual suffering from emergency respiratory distress, especially in the field setting, is one of the hardest tasks facing a medical professional. Whatever the cause of the difficulty in breathing, the highest priority of the attending medical professional is to establish and maintain an unobstructed airway in the victim, thus insuring that an adequate amount of oxygen is being received by the patient.
Frequently, the preferred way of establishing an adequate supply of oxygen to a patient suffering from emergency respiratory distress is nasal endotracheal intubation, a procedure in which a breathing tube called an endotracheal tube is inserted into the trachea of a patient. For example, in the case of a trauma victim, a medical professional qualified to perform the nasal endotracheal intubation procedure, who will usually be a paramedic but might also be a physician, first places the head of the victim in a neutral position to insure against damage of the cerebral spine. While keeping the head of the victim in this neutral position, the medical professional inserts the endotracheal tube, typically, a flexible plastic tube open at either end, into a nare, or nostril hole, of the victim and pushes the tube through the nasal cavity, past the larynx, and finally into the trachea. The nasal endotracheal tube, which is usually used for this procedure, is modified to include a handle, which is usually ring shaped, attached to the tube by a string. Thus, the medical professional can use the handle to pull the tube into a shape necessary for navigating the tube through the nasal cavity and into the trachea. After insuring that the endotracheal tube is correctly fitted into the trachea, the medical professional uses a syringe to blow air into an air valve, which inflates a small bulb located near the end of the endotracheal tube, thus sealing the tube against the wall of the trachea. At this point, the medical professional can attach a bag valve device to an adaptor found on the exterior end of the endotracheal tube, thus placing the bag valve device in gaseous communication with the endotracheal tube, which insures that the victim is receiving an adequate supply of oxygen. Almost all endotracheal tubes will have this adaptor, which has a standard size tube extending from one side for attaching the bag valve device to the adaptor and, extending from the opposite side, a second tube of whatever size is necessary to fit within the diameter of the endotracheal tube, which comes in different widths based upon the size of the patient undergoing the procedure. After attaching the bag valve device, the medical professional can then treat any other medical conditions present. If the procedure was not performed while en route to a hospital, the victim will then be transported to a hospital.
While nasal tracheal intubation is the preferred way of establishing an unobstructed airway, a medical professional using this procedure often encounters various difficulties while trying to perform it, whether in the field or in a clinical setting. Since the procedure is a blind procedure, the attending medical professional must rely upon the intensity and characteristics of the breathing sounds exiting the patient to properly guide the endotracheal tube through the oropharynx and past the larynx into the trachea. Moreover, since the patient's ventilation may be interrupted by endotracheal intubation, the procedure should be completed within a maximum time of thirty seconds, more preferably fifteen to twenty seconds, to insure that the patient does not suffer any cell damage to the brain or other organs due to oxygen deprivation.
During this procedure, the medical professional usually is required to put his or her ear next to the exterior end of the endotracheal tube to listen for the intensity of the breathing sounds of the patient, using these sounds as a guide for properly placing the tube. This ear to tube method of performing the procedure has many disadvantages. First, the medical professional may not be able to hear the breathing sounds well enough to accurately guide the tube, either because the sounds are too faint or because of extraneous noise, such as sirens from emergency vehicles or the actions of bystanders. Second, the medical professional can be exposed to medical hazards exiting the body of the victim, including airborne pathogens and potentially dangerous bodily fluids, such as blood. Moreover, standard medical precautions, such as goggles, gloves, and masks, are not entirely satisfactory to prevent infection of the attending medical professional because the ear, and therefore the outer ear canal, must be exposed while performing this procedure. Pathogens or bodily fluids entering the outer ear canal can possibly cause infection there or elsewhere in the body.
It is also known in the prior art to remove the bell from the end of a single tube stethoscope cord and force the end of the stethoscope cord through the tubes of the adaptor on the exterior end of the endotracheal tube and into the exterior opening of the endotracheal tube to listen for the intensity of the breathing sounds while performing a nasal endotracheal intubation procedure. This cord into tube method increases the medical professional's ability to hear the victim's breathing sounds while providing increased protection from airborne and fluidborne pathogens.
However, there are still a number of significant disadvantages with the use of the cord into tube method. Since the stethoscope cord must be snugly inserted into the endotracheal tube for this method to be effective, it can not be used with small diameter endotracheal tubes, which are used with children, because the cord is unable to fit within the diameter of the tube. Even if the attending medical professional tries to hold the end of the cord in the adaptor with one hand, the quality of the breathing sounds will be greatly diminished; in addition, it will be difficult, if not impossible, to properly guide and insert the tube while using only one hand. Even when the cord does properly fit into the endotracheal tube, the flow of oxygen into the endotracheal tube, and thus, into the patient, is severely restricted, if not shut off entirely, during the time the procedure is being performed. Additionally, if it should become necessary to clear out blockage within the endotracheal tube by use of a remote suction device, the stethoscope cord must fist be unwedged from the endotracheal tube. Because of the time limits for performing the nasal endotracheal intubation procedure, the time needed to remove the cord and use the catheter, which will typically be ten seconds or more, is a critical drawback in using the cord into tube method. Finally, the stethoscope cord can easily become contaminated by any bodily fluids exiting the endotracheal tube, which will also have the effect of diminishing the ability of the medical professional to hear the patient's breathing sounds, and any airborne pathogens exiting the endotracheal tube will be constrained within the stethoscope cord, which increases the chances of the medical professional being infected by such pathogens. Thus, this method has also proven to be a less than satisfactory way of monitoring breathing sounds.
Various devices have been invented for connecting a stethoscope to an endotracheal tube to allow different types of medical personnel to better monitor patient breathing sounds. For example, U.S. Pat. No. 5,056,514, issued to "Dupont" on Oct. 15, 1991, describes a device that permits an anesthesiologist, or some other medical personnel, to monitor a surgical patient's breathing sounds with a stethoscope while anesthesia gas is being administered through an endotracheal tube placed visually through the surgical patient's mouth cavity and into the trachea. A stethoscope is connected to the device but is separated from the flow of gas by an impermeable membrane serving to prevent free flow of the anesthesia gas into the stethoscope tube. In order to hear the breathing sounds, it is necessary for the sounds to pass through the membrane for detection by a stethoscope attached to a chamber formed above the membrane.